EP0540961B1 - Verfahren und Einrichtung zur Kompression von sich bewegenden Videobildern mit adaptiver Bitzuordnung und Quantisierung - Google Patents

Verfahren und Einrichtung zur Kompression von sich bewegenden Videobildern mit adaptiver Bitzuordnung und Quantisierung Download PDF

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EP0540961B1
EP0540961B1 EP92118193A EP92118193A EP0540961B1 EP 0540961 B1 EP0540961 B1 EP 0540961B1 EP 92118193 A EP92118193 A EP 92118193A EP 92118193 A EP92118193 A EP 92118193A EP 0540961 B1 EP0540961 B1 EP 0540961B1
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picture
pictures
bits
bit
compression coding
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Cesar Augusto Gonzales
Eric Viscito
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International Business Machines Corp
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Definitions

  • the present invention relates to the field of data compression and, more particularly, to a method and a system and techniques for compressing digital motion video signals in keeping with algorithms similar to the emerging MPEG standard proposed by the International Standards Organization's Moving Picture Experts Group (MPEG).
  • MPEG Moving Picture Experts Group
  • the present invention may be applied in connection with such an encoder, in order to facilitate an understanding of the invention, some pertinent aspects of the MPEG video compression algorithm will be reviewed. It is to be noted, however, that the invention can also be applied to other video coding algorithms which share some of the features of the MPEG algorithm.
  • Step 2 and 3 are lossless, i.e., the original data is faithfully recoverable upon reversal, and Step 2 is known as entropy coding.
  • Step 1 can be either lossless or lossy in general. Most video compression algorithms are lossy because of stringent bit-rate requirements. A successful lossy compression algorithm climinates redundant and irrelevant information. allowing relatively large errors where they are not likely to be visually significant and carefully representing aspects of a sequence to which the human observer is very sensitive.
  • Step 1 The techniques employed in the MPEG algorithm for Step 1 can be described as predictive/interpolative motion-compensated hybrid DCT/DPCM coding.
  • Huffman coding also known as variable length coding (see the above- cited HUFFMAN 1952 paper) is used in Step 2.
  • the MPEG standard is really a specification of the decoder and the compressed bit stream syntax, the following description of the MPEG specification is, for ease of presentation, primarily from an encoder point of view.
  • the MPEG video standard specifies a coded representation of video for digital storage media, as set forth in ISO-IEC JTC1/SC2/WG11 MPEG CD-11172, MPEG Committee Draft, 1991.
  • the algorithm is designed to operate on noninterlaced component video.
  • Each picture has three components: luminance (Y), red color difference ( C r ), and blue color difference ( C b ).
  • the C r and C b components each have half as many samples as the Y component in both horizontal and vertical directions.
  • An MPEG data stream consists of a video stream and an audio stream which are packed, together with systems information and possibly other bitstreams, into a systems data stream that can be regarded as layered.
  • the compressed data is further layered.
  • the layers pertain to the operation of the compression algorithm as well as the composition of a compressed bit stream.
  • the highest layer is the Video Sequence Layer, containing control information and parameters for the entire sequence.
  • a sequence is subdivided into sets of consecutive pictures, each known as a Group of Pictures (GOP).
  • GOP Group of Pictures
  • a general illustration of this layer is shown in Figure 1. Decoding may begin at the start of any GOP, essentially independent of the preceding GOP's. There is no limit to the number of pictures which may be in a GOP, nor do there have to be equal numbers of pictures in all GOP's.
  • the third or Picture layer is a single picture. A general illustration of this layer is shown in Figure 2.
  • the luminance component of each picture is subdivided into 16 ⁇ 16 regions; the color difference components are subdivided into 8 ⁇ 8 regions spatially co-sited with the 16 ⁇ 16 luminance regions. Taken together, these co-sited luminance region and color difference regions make up the fifth layer, known as a macroblock (MB).
  • MB macroblock
  • Macroblocks in a picture are numbered consecutively in lexicographic order, starting with Macroblock 1.
  • Each slice consists of some number of consecutive MB's. Slices need not be uniform in size within a picture or from picture to picture. They may be only a few macroblocks in size or extend across multiple rows of MB's as shown in Figure 3.
  • the Sequence, GOP, Picture, and slice layers all have headers associated with them.
  • the headers begin with byte-aligned Start Codes and contain information pertinent to the data contained in the corresponding layer.
  • I-pictures Intramode pictures
  • B-pictures bidirectionally motion-compensated pictures
  • I- and P-pictures collectively as anchor pictures
  • a GOP must contain at least one anchor picture, and may contain more.
  • B-pictures there may be zero or more B-pictures.
  • An illustration of a typical GOP is shown in Figure 5.
  • transform coding One very useful image compression technique is transform coding .
  • transform coding See N.S. JAYANT and P. NOLL, Digital Coding of Waveforms, Principles and Applications to Speech and Video , Englewood Cliffs, NJ: Prentice-Hall, 1984, and A.G. TESCHER, "Transform Image Coding," in W.K. Pratt, editor, Image Transmission Techniques, pp. 113-155, New York, NY: Academic Press, 1979.
  • DCT discrete cosine transform
  • K.R. RAO and P. YIP Discrete Cosine Transform, Algorithms, Advantages, Applications, San Diego, CA: Academic Press, 1990, and N.
  • the compression of an I-picture is achieved by the steps of 1) taking the DCT of blocks of pixels, 2) quantizing the DCT coefficients, and 3) Huffman coding the result.
  • the DCT operation converts a block of n ⁇ n pixels into an n ⁇ n set of transform coefficients.
  • the MPEG algorithm uses a DCT block size of 8 ⁇ 8.
  • the DCT transformation by itself is a lossless operation, which can be inverted to within the precision of the computing device and the algorithm with which it is performed.
  • the second step, quantization of the DCT coefficients is the primary source of lossiness in the MPEG algorithm. Denoting the elements of the two-dimensional array of DCT coefficients by csubmn , where m and n can range from 0 to 7; aside from truncation or rounding corrections, quantization is achieved by dividing each DCT coefficient c mn by w mn ⁇ QP , with w mn being a weighting factor and QP being the quantizer parameter . Note that QP is applied to each DCT coefficient.
  • the weighting factor w mn allows coarser quantization to be applied to the less visually significant coefficients. There can be two sets of these weights, one for I-pictures and the other for P- and B-pictures.
  • Custom weights may be transmitted in the video sequence layer, or defaults values may be used.
  • the quantizer parameter QP is the primary means of trading off quality vs. bit-rate in MPEG. It is important to note that QP can vary from MB to MB within a picture. This feature, known as adaptive quantization (AQ), permits different regions of each picture to be quantized with different step-sizes, and can be used to attempt to equalize (and optimize) the visual quality over each picture and from picture to picture.
  • AQ adaptive quantization
  • algorithms which consist of rules for the use of AQ to improve visual quality are not subject to standardization.
  • a class of rules for AQ is one object of this invention.
  • the DCT coefficient information for each MB is organized and coded, using a set of Huffman codes. As the details of this step are not essential to an understanding of the invention and are generally understood in the art, no further description will be offered here. For further information in this regard reference may be had to the previously-cited HUFFMAN 1952 paper.
  • Motion compensation requires some means for modeling and estimating the motion in a scene.
  • each picture is partitioned into macroblocks and each MB is compared to 16 ⁇ 16 regions in the same general spatial location in a predicting picture or pictures.
  • the region in the predicting picture(s) that best matches the MB in some sense is used as the prediction.
  • the difference between the spatial location of the MB and that of it's predictor is referred to as a motion vector .
  • the outputs of the motion estimation and compensation for an MB are motion vectors and a motion-compensated difference macroblock.
  • the time interval between a P-picture and its predicting picture can be greater than one picture interval.
  • backward-in-time prediction may be used in addition to forward-in-time prediction (see Figure 5).
  • Such pictures are known as bidirectionally motion-compensated pictures, B-pictures.
  • interpolative motion compensation is allowed in which the predictor is an average of a block from the previous predicting picture and a block from the future predicting picture. In this case, two motion vectors are needed.
  • bidirectional motion compensation leads to a two-level motion compensation structure, as depicted in Figure 5.
  • Each arrow indicates the prediction of the picture touching the arrowhead using the picture touching the dot.
  • Each P-picture is motion-compensated using the previous anchor picture (I-picture or P-picture, as the case may be).
  • an MPEG-1 sequence consists of a series of I-pictures which may have none or one or more P-pictures sandwiched between them.
  • the various I- and P-pictures may have no B-pictures or one or more B-pictures sandwiched between them, in which latter event they operate as anchor pictures.
  • the MPEG algorithm is intended to be used primarily with fixed bit-rate storage media. However, the number of bits in each picture will not be exactly constant, due to the different types of picture processing, as well as the inherent variation with time of the spatio-temporal complexity of the scene being coded.
  • the MPEG algorithm uses a buffer-based rate control strategy to put meaningful bounds on the variation allowed in the bit-rate.
  • a Video Buffer Verifier (VBV) is devised in the form of a virtual buffer. whose sole task is to place bounds on the number of bits used to code each picture so that the overall bit-rate equals the target allocation and the short-term deviation from the target is bounded.
  • This rate control scheme can be explained as follows. Consider a system consisting of a buffer followed by a hypothetical decoder.
  • the buffer is filled at a constant bit-rate with compressed data in a bit stream from the storage medium. Both the buffer size and the bit-rate are parameters which are transmitted in the compressed bit stream.
  • the hypothetical decoder instantaneously removes from the buffer all of the data associated with the first picture. Thereafter, at intervals equal to the picture rate of the sequence, the decoder removes all data associated with the earliest picture in the buffer.
  • U VRV and L VRV upper and lower bounds on the number of bits allowed in each picture.
  • the upper and lower bounds for a given picture depend on the number of bits used in all the pictures preceding it. It is the function of the encoder to produce bit streams which satisfy this requirement. It is not expected that actual decoders will be configured or operate in the manner described above. The hypothetical decoder and it's associated buffer are simply a means of placing computable limits on the size of compressed pictures.
  • One important function of an MPEG encoder is to ensure that the video bitstream it produces satisfies these bounds. There are no other restrictions on the number of bits used to code the pictures in a sequence. This latitude should be used to allocate the bits in such a way as to equalize (and optimize) the visual quality of the resulting reconstructcd pictures. A solution to this bit allocation problem is another object of this invention.
  • the purpose of the MPEG standard is to specify the syntax of the compressed bit stream and the methods used to decode it.
  • Considerable latitude is afforded encoder algorithm and hardware designers to tailor their systems to the specific needs of their application.
  • the degree of complexity in the encoder can be traded off against the visual quality at a particular bit-rate to suit specific applications.
  • a large variety of compressed bit-rates and image sizes are also possible. This will accommodate applications ranging from low bit-rate videophones up to full-screen multimedia presentations with quality comparable to VHS videocassette recordings.
  • the problem to which the present invention is addressed is achieving compression of digital video sequences in accordance with the MPEG standard, applying techniques of the type discussed above using adaptive quantization and bit-rate control in a manner that optimizes the visual quality of the compressed sequence while ensuring that the bit stream satisfies the MPEG fixed bit-rate requirements.
  • C-T. CHEN and D.J. LeGALL describe an adaptive scheme for selecting the quantization factor based on the magnitude of the k - th largest DCT coefficient in each block in their article "A K-th Order Adaptive Transform Coding Algorithm for Image Data Compression," SPIE Vol. 1153, Applications of Digital Image Processing XIL vol. 1153, pp, 7-18, 1989.
  • H. LOHSCHELLER proposes a technique for classifying blocks in "A Subjectively Adapted Image Communication System," IEEE Trans. Communications, vol. COM-32, pp. 1316-1322, December 1984. This technique is related to adaptive zonal sampling and adaptive vector quantization.
  • K.N. NGAN, K.S. LEONG, AND H. SINGH in "A HVS-weighted Cosine Transform Coding Scheme with Adaptive Quantization," SPIE Vol. 1001 Visual Communications and Image Processing, vol. 1001, pp. 702-708, 1988, propose an adaptive quantizing transform image coding scheme in which a rate controlling buffer and the contrast of the DC term of each block with respect to its nearest neighbor blocks in raster scan order are used in combination to adapt the quantizer factor.
  • H. HOELZLWIMMER discusses in "Rate Control in Variable Transmission Rate Image Coders," SPIE Vol. 1153 Applications of Digital Image Processing XII, vol. 1153, pp. 77-89, 1989, a combined bit-rate and quality controller. Two parameters are used to control the reconstruction error and bit-rate, quantizer step size and spatial resolution. A spatial domain weighted mean square error measure is used to control the parameters.
  • US Patent 5 051 840 discloses a picture signal coding device which divides picture data into a plurality of blocks and subjects the individual blocks of picture data to an orthogonal transform, a normalization, and a coding.
  • the compression coding is directed to STILL PICTURE DATA.
  • the amounts of data to be allocated to the individual blocks are determined on the basis of the ratios of activities of the individual blocks to a sum of the block-by-block activities, whereby the output of the individual block of coded data is restricted.
  • the amount of data is allocated in matching relation to the frequency components of the individual blocks. Further, the number of bits to be assigned to the entire picture is maintained constant.
  • the present invention discloses a method and a system for performing a picture bit allocation in accordance with claims 1 and 6 respectively.
  • the method and the system are applicable to video compression algorithms intended to produce a fixed-bit-rate compressed data stream, and in which motion compensation is employed.
  • This method of allocating bits among the successive pictures in a video sequence results in a visual quality from picture to picture, while meeting the MPEG Video Buffer Verifier (VBV) bit-rate limitations.
  • VBV MPEG Video Buffer Verifier
  • an important feature of the ISO/IEC MPEG standard is that only the syntax of the compressed bit stream and the method of decoding it are specified in detail. Therefore, it is possible to have different encoders, all of which produce bit streams compatible with the syntax of the standard, but which are of different complexities, and result in different levels of visual quality at a given bit-rate.
  • the MPEG standard applies primarily, but not exclusively, to situations in which the average bit-rate of the compressed data stream is fixed.
  • the MPEG specification contains a precise definition of the term "fixed bit-rate". However, even though the average rate must be constant, the number of bits allocated to each picture in an MPEG video sequence does not have to be the same for all pictures. Furthermore, allocation of bits within a picture does not have to be uniform. Part of the challenge in designing an encoder that produces high quality sequences at low bit-rates is developing a technique to allocate the total bit budget among pictures and within a picture.
  • adaptive quantization This technique permits different regions of each picture to be coded with varying degrees of fidelity, and can be used in image and motion video compression to attempt to equalize (and optimize) the visual quality over each picture and from picture to picture.
  • AQ adaptive quantization
  • the MPEG standard allows adaptive quantization, algorithms which consist of rules for the use of AQ to improve visual quality are not prescribed in the standard.
  • pre-processing Another broad class of techniques that can be applied in an MPEG or similar encoder is generally referred to as pre-processing. Any sort of pre-processing of a digital video sequence which does not change the fundamental spatial relationship of the samples to one another may be incorporated into an MPEG-compatible encoder for the purpose of improving the visual quality of the compressed sequence. Examples of this include linear or nonlinear pre-filtering.
  • FIG. 6 a block diagram of an MPEG encoder incorporating three component subsystems for implementing the above-mentioned techniques in accordance with the present invention is shown in Figure 6.
  • picture data P k representative of the k-th picture in a sequence enters one subsystem.
  • QP-adaptive Pre-processor 3 where pre-processing may take place if appropriate.
  • the nature of the pre-processing is controlled by quantization levels ( QP prev ) of previously coded pictures, which will have been previously communicated to subsystem 3 from Adaptive-quantizing Rate-controlled (AQ/RC) Picture Coder 1. in the coarse of coding the data sequence.
  • QP prev quantization levels
  • AQ/RC Adaptive-quantizing Rate-controlled
  • the possibly pre-processed picture data F k output by subsystem 3 enters the next subsystem, AQ/RC Picture Coder 1, where motion estimation and MB classification take place.
  • Some of the results of these operations within the AQ/RC Picture Coder 1 ( D k ) are passed to the remaining subsystem, Picture Bit Allocation subsystem 2, and a target number of bits for the picture data F k is passed back ( A k , S k , and C k ) to the AQ/RC Picture Coder 1. Coding then proceeds, as is described in more detail below.
  • compressed data for picture data F k , CD k is output from the AQ/RC Picture Coder 1.
  • data relating to the number of bits required to code F k ( B k ) and the reconstruction error ( E k ) are passed to the Picture Bit Allocation subsystem 2, and the previous quantization level QP prev , which may be an average value, QP avg is passed to the QP-adaptive Pre-processor subsystem 3, for use in processing future frames.
  • QP prev which may be an average value
  • the operation of the Picture-to-Picture Bit Allocation subsystem 2 will first be explained, followed by an explanation of the functioning of the AQ/RC Picture Coder subsystem 1, and then the QP-adaptive Pre-processor subsystem 3 will be described. It may be helpful for a full understanding of the relationship of the invention to the MPEG video compression algorithm to refer to the afore-cited MPEG CD-11172 and to ISO-HEC JTC1/SC2/WG11 MPEG 91/74, MPEG Video Report Draft, 1991, or D. LeGALL, "MPEG: A Video Compression Standard for Multimedia Applica- tions," Communications of the ACM, vol. 34, April 1991.
  • Video compression algorithms employ motion compensation to reduce the amount of data needed to represent each picture in a video sequence.
  • fixed-bit-rate compression algorithms must maintain an overall average bit-rate near a specified target, they often have some latitude in the number of bits assigned to an individual picture. Assigning exactly the same number of bits to each picture produces a compressed sequence whose quality fluctuates with time, a phenomenon which is visually distracting to the viewer.
  • the Picture Bit Allocation subsystem 2 involves procedures for allocating bits among compressed pictures in a video sequence. It is applicable specifically to video compression algorithms intended to produce a fixed-bit-rate compressed data stream, and in which motion compensation is employed, e.g., the ISO/IEC MPEG video compression standard.
  • a Picture Bit Allocation system would allocate a number of bits to each picture in such a way that the perceived visual quality of the coded sequence was uniform from picture to picture and equal to the optimum attainable at the given bit-rate, subject to bit allocation limitations imposed by the fixed-bit-rate rules.
  • such a system would require knowledge of the contents of the entire sequence prior to coding the first picture or frame. It would also require a priori knowledge of the visual quality that reconstructed pictures would have when coded using a given bit allocation.
  • the first requirement is impractical because of the potentially large storage and delay implied.
  • the second is currently very difficult because a mathematically tractable model of the perceived visual quality of coded visual data is not known, even when the coded and original pictures are available.
  • the Picture Bit Allocation subsystem of the present invention provides a practical solution to this problem by keeping track of a measure of the difficulty in coding pictures of each type in the recent past.
  • This measure referred to as the coding difficulty, depends on the spatial complexity of a picture and the degree to which motion compensation is able to predict the contents of a picture.
  • Bits are allocated to the three picture types in amounts dependent on the relative coding difficulties of the three types. Additionally, the three allocations computed at each picture (one for each picture type) are such that, if an entire Group of Pictures (GOP) were coded using those allocations, the number of bits required would equal the target bit-rate.
  • GOP Group of Pictures
  • the Picture Bit Allocation subsystem 2 determines how many bits to allocate to picture k after the data F k for that picture has been analyzed in the AQ/RC Picture Coder 1, and the coding difficulty factor of the picture has been passed from the AQ/RC Picture Coder 1 to the Picture Bit Allocation subsystem 2, but prior to coding the picture.
  • the Picture Bit Allocation subsystem 2 also uses information pertaining to previously coded pictures, which the AQ/RC Picture Coder 1 is assumed to have already passed to the Picture Bit Allocation subsystem 2. Specifically, this information consists of B k , the number of bits used to code the most recent picture of each type (broken into transform coefficient bits and side bits), and E r , the reconstruction error of the most recent two anchor pictures.
  • n I I-pictures
  • n P P-pictures
  • n B B-pictures
  • the allocation operation about to be described begins by considering an allocation for the selected set of pictures, although the final result will be three picture bit allocations, one for each picture type, and only the picture bit allocation for the picture type corresponding to the type of the picture about to be coded will be used.
  • B avg is the average picture bit allocation consistent with the target bit rate.
  • the bits allocated to the set of pictures, and those allocated to each picture fall into two classes: side bits ( S ) and coefficient bits ( C ).
  • S is taken to include all coded data other than coded transform coefficient data.
  • Side bits are assigned to include picture header information and all side information; for example, the motion compensation mode information, motion vectors, and adaptive quantization data.
  • Coefficient information is contained only in the bits used to code the transform coefficients of the pixel data itself (in the case of I-pictures), or the pixel difference data (in the P- and B-picture cases).
  • the side information bit allocation for the next picture to be coded is set equal to the actual number of bits required to code the side information in the most recent picture of the same type in the sequence.
  • An alternative method of computing the side bit information allocation is to use an average of the actual numbers of bits required to code several or all past pictures of the same type in the sequence. It is also possible to ignore the side information allocations in this procedure, and to compute the picture bit allocation based solely on the transform coefficient bit allocation. This latter approach can be done, in the context of the following discussion, by assuming all side allocation variables S x are equal to 0.
  • C I , C P , and C B are found as the unique solution to the equations:
  • C set n I C I + n P C P + n B C B ,
  • the initial equation (for C set ) in this set ensures that the overall set average is correct.
  • the foregoing method is valuable, because it accounts for the spatial complexity of the sequence through the three coding difficulty factors, D I , D P , and D B , for the success of the motion compensation through D P and D B , the target bit-rate through the requirement of the initial equation for C set and the quality of recently coded pictures through E r and E' r .
  • the above bit allocation strategy results in an allocation that exceeds U VBV or falls below L VBV .
  • the frequency with which this happens depends on the size of the VBV buffer and on the nature of the sequence.
  • a typical scenario is when the VBV buffer is relatively small (e.g., six average pictures or less), and the motion compensation is very successful.
  • the allocation strategy attempts to give virtually all of the transform bits for a set to the I-pictures, resulting in an allocation for an individual picture larger than the VBV buffer size.
  • the I-picture allocation is chipped to fall a small amount inside the corresponding VBV limit, and the bits taken from the I-picture are re-allocated to the P-picture.
  • coefficient and side information can be ignored, by using the coding difficulty estimate to allocate all the bits for a picture. In such a case, the coding difficulty estimate could factor in the difficulty of coding side information directly, or ignore side information completely.
  • this subsystem involves procedures for the adaptive quantization (AQ) of the successive pictures of a video sequence to achieve improved visual quality, while ensuring that the number of bits used to code each picture is close to a predetermined target. Procedures are performed for I-pictures, P-pictures, and B-pictures. These procedures involve treating the spatial regions making up a picture using a region classification strategy which works in tandem with:
  • Figure 11 generally illustrates the components of the AQ/RC Picture Coder 1.
  • the operation of this subsystem depends on the type of picture being coded.
  • a video picture signal F k for a picture k , which may or may not have been pre-processed in the QP-adaptive Pre-processor 3, enters a Motion Estimation and MB Classification unit 14 of the AQ/RC Picture Coder 1.
  • the signal is analyzed and each MB is classified according to procedures described below. If the picture is a P-picture or B-picture, motion estimation is also performed. Results of these operations in the form of a coding difficulty factor, D k , are passed to the Picture Bit Allocation subsystem 2, for use as detailed above.
  • the Picture Bit Allocation subsystem 2 then returns a bit allocation signal C k for picture k .
  • This bit allocation signal is used by a QP-level Set unit 15, along with a set of information passed from the Motion Estimation and MB Classification unit 14, to determine initial values of the quantization factor QP to be used in coding each MB. Additionally, the QP-level Set unit 15 computes an estimate of the number of bits required to code each row of MB's in the picture.
  • These quantization factors and row targets are passed to the Rate-controlled Picture Coder unit 16, which proceeds to code the picture, also using information passed from the Motion Estimation and MB Classification unit 14. Since the operation of the AQ/RC Picture Coder 1 is partitioned among three sub-units the description that follows will follow the same partition while referring primarily to Figure 11.
  • One of the primary purposes of the Motion Estimation and MB Classification unit 14 is to determine which coding mode m ( r,c ) will be used to code each MB in a picture. This function is only used for motion compensated pictures, since there is only one mode for MB's in I-pictures: intramode. The mode decision relies on a motion estimation process, which also produces motion vectors and motion-compensated difference MB's. Another important function of the Motion Estimation and MB Classification unit 14 is to classify each MB. The class cl ( r , c ) of MB ( r , c ) will ultimately determine the value of the quantization factor QP ( r , c ) used to code that MB. The modes and classes are determined by analyzing each picture, and estimating the motion between the picture to be coded and the predicting picture(s). The same information is also used to compute the coding difficulty factor, D k , which is passed to the Picture Bit Allocation subsystem 2.
  • the motion-compensated difference MB is the pixel-wise difference between the current MB under consideration and the predicting MB.
  • the exact method for forming the prediction MB depends on the motion compensation mode employed, and is detailed in the above-noted ISO-IEC JTC1/SC2/WG11 MPEG CD-11172, MPEG Committee Draft, 1991.
  • the motion vector should, in some sense, be indicative of the true motion of the part of the picture with which it is associated. Details of motion estimation techniques can be found in A. N. NETRAVALI AND B. G. HASKELL, Digital Pictures: Representation and Compression New York, NY: Plenum Press, 1988.
  • a full search motion estimation algorithm was used covering a range of ⁇ 7 ⁇ n pixels in the horizontal and vertical directions, where n is the distance in picture intervals between the picture being analyzed and the predicting picture, and where the motion vectors are accurate to half a pixel.
  • the present invention involves techniques for using the results of motion estimation to code video sequences, but is not limited to use with any specific motion estimation techniques, and can be used with any motion estimation method, provided that a measure of the success of motion compensation (motion compensation error), that indicates how good the match is between the MB being compensated and the predicting region pointed to by the motion vector, can be made available.
  • the forward motion vector for MB ( r , c ) may be denoted as mv f ( r , c ), and the backward motion vector as mv b ( r , c ).
  • the interpolative mode uses both forward and backward vectors.
  • the forward, backward, and interpolative motion compensation errors may be denoted as ⁇ mc,f ( r , c ), ⁇ mc,b ( r , c ), and ⁇ mc,i ( r , c ), respectively.
  • ⁇ ( r , c ) a measure of the spatial complexity of each MB is needed. Denote this measure as ⁇ ( r , c ). It is important that ⁇ ( r , c ). ⁇ mc,f ( r , c ), ⁇ mc,b ( r , c ), and ⁇ mc,i ( r , c ), are like measures, in the sense that numerical comparision of them is meaningful. In the preferred embodiment, these measures are all defined to be mean absolute quantities, as indicated below.
  • the spatial complexity measure for MB ( r , c ) is taken to be the mean absolute difference from DC, and is given by where
  • the coding difficulty factors passed to the Picture Bit Allocation subsystem 2 are based completely on the above measures of spatial complexity and motion compensation error.
  • the total difficulty factor is
  • the coding mode is first decided upon, and the measure associated with that mode is used in a summation similar to the one above.
  • the following modes being possible:
  • the mode selection rule used for B-pictures is: the mode with the lowest ⁇ ( r , c ) is used to code the MB. It is to be appreciated that, although mean absolute quantities were used as the measures of coding difficulty in the preferred embodiment, any like measures (for example, mean square quantities) could also be used.
  • the MB's are classified as follows.
  • the class of all intramode MB's is computed by quantizing the minimum value of ⁇ k ( r , c ) for that MB. Defining a threshold t , the class cl ( r , c ) of MB ( r , c ) is given by
  • B-picture MB's are not classified, the Q-level Set unit 15 is not used, and the coding scheme employed in the RC Picture Coder unit 16 is simpler than that used for I-pictures and P-pictures.
  • the function of the QP-level Set unit 15 is to compute an initial value for the quantizer step size for each class. All MB's in a given class are assigned the same quantization step size.
  • Values of ⁇ QP that have been used in the preferred embodiment are 5 and 6.
  • the allowed range for QP low in the preferred embodiment is - 31,..., 31, although MPEG only allows for integer values of QP ( r , c ) in the range of 1,..., 31. Therefore, whenever the above formula produces a value above 31, it is clipped to 31, and any values which fall below 1 are clipped to 1. It is beneficial to allow QP low to be less than 1 to ensure that the finest quantizer step sizes can be applied to MB's of all classes, if the bit-rate warrants it. The process for selecting the initial value QP init / low of QP low is explained below.
  • the underlying model of human perception of coding errors used in the preferred embodiment, as reflected in the method for computing the class cl ( r , c ) of each MB and for computing QP ( r , c ), given cl ( r , c ), is that like-magnitude errors are more visible in less active regions of a picture. While this model is clearly an over-simplification, it is a reasonable compromise between visual quality and computational burden.
  • the rationale behind using the minimum ⁇ k over the four luminance blocks in the MB for classification, rather than the ⁇ of the entire block, is that MB's with any smooth regions should be assigned a low quantizer step size.
  • the MB modes m ( r , c ) and classes cl ( r , c ) are used along with the ⁇ ( r , c ) and ⁇ mc ( r , c ) values and the target bit-rate for the picture transform coefficients to set the initial quantizer low value QP low .
  • a model has been developed in accordance with the invention which predicts the number of bits required to code the transform coefficients of an MB, given the quantization value to be used and ⁇ (in the case of intramode MB's) or ⁇ mc (for motion-compensated MB's).
  • Experimental data leads to a model of the form: for intramode MB's and for motion-compensated MB's.
  • the result is a two-dimensional data set which indicates the average number of bits required to code MB's as a function of the ⁇ value of the MB and the QP step size used to code it. These average values may be denoted as It is desired to fit these measured values to an equation of the form:
  • the linear parameters a I and a P should be adjusted after coding each I- or P-picture, to track the dynamically changing characteristics of the video sequence. This can be done according to a method which will be described in detail in the description of the RC Picture Coder unit 16 below. (For intramode MB's, this model can be improved by adding an additional term to account for the number of bits required to code the DC terms in the MB, since the coding for DC coefficients is handled separately.)
  • the initial value for QP low is taken as that value of QP for which B ( QP ) is closest to the picture transform coefficient allocation C :
  • a half-interval search is conducted between - 31 and 31 to find QP init / low .
  • the role of the upper and lower bounds on QP in this procedure is subtle. While an upper bound of 31 is sufficient to guarantee that the encoder can operate with the coarsest possible quantization allowed by the standard, a larger upper bound will change the performance of the rate control algorithm, as will be described below in greater detail, by making it more sensitive to the over-production of bits. Similar properties hold for the lower bound on QP .
  • the QP-level Set unit 15 computes the expected number of bits required to code row r of MB's using QP low , by where N row is the number of rows of MB's.
  • the second term in this expression accounts for the difference between the number of bits predicted by the model at QP low and the actual transform coefficient allocation C, and the third term accounts for each row's share of the side information allocation S.
  • the sum of the targets T( r ) over all the rows yields the total picture allocation A .
  • These expected values become target row bit-rates for the RC Picture Coder unit 16.
  • Picture coding proceeds by indexing through the MB's and coding each according to the mode and quantizer step sizes determined in the previous steps. However, because of mismatches in the bit-rate model and the continual changing of the contents of a sequence, the actual number of bits produced will not exactly match the expected number. It is desired to control this deviation, not only to keep the actual bits produced for the picture close to the target, but also to prevent violation of the VBV bit-rate limitations.
  • a rate control feedback strategy has been developed in accordance with the invention which updates QP low at the end of each row of MB's. A number of factors determine the update.
  • One factor is that different rows of MB's in a picture are not expected to produce the same number of bits, because of variations in ⁇ ( r , c ) and ⁇ mr ( r , c ), as well as assigned quantizer step sizes.
  • the number of bits produced is compared to the expected number 7( r ) computed in the QP-level Set unit 15.
  • Another factor which plays a role in updating QP low is the closeness of both the picture allocation and the actual number of bits produced to the VBV limit.
  • the gain of the QP low update as a function of bit-rate deviations is a function of the proximity of the VBV limit in the direction of the error.
  • This strategy updates QP low based on the total bit allocation error up to the current row, as it relates to the maximum error allowed according to the VBV criterion.
  • bit-rate model parameters ( a I and a P ) are computed so that the bit-rate model will agree with the number of transform coefficient bits actually produced ( C a ).
  • C a the number of transform coefficient bits actually produced
  • a value of ⁇ 0.667 may be used in the implementation.
  • a similar strategy is used to update both a I and a P after coding a P-picture.
  • ⁇ is proportional to the fraction of MB's coded in the mode corresponding to the bit-rate model parameter being updated.
  • the number of bits used to code all side information for the picture is stored for use as the value of the side information allocation S for the next picture of the same type.
  • Figure 13 shows the QP low and average QP in each row of frames 16, 22, 61, and 67 of the test sequence. It should be understood that, if the initial guess for QP low and the bit-rate models were exact, there would never be any change in QP low from row to row. However, QP avg would fluctuate depending on the spatial activity and motion compensability of the different rows in the pictures. For instance, it can easily be seen, from the I-picture QP values, that the lower half of the rows of the Flower Garden segment is far more complex spatially than the upper half. The P-picture results show that motion compensation reduces the variation in QP avg . and Figure 14 shows the bits produced versus the targets on a row by row basis. The results can be seen to track the targets reasonably well.
  • the rate control method for B-pictures differs from that of I- and P-pictures.
  • No MB classification has been done, and hence no attempt is made to estimate the amount of compressed data each row of MB's will produce. Thus all row targets in a picture are the same.
  • the quantizer factor is set equal to the value it had at the end of the previous B-picture.
  • the foregoing presents a motion video coder procedure which uses adaptive bit allocation and quantization to provide robust, high quality coded sequences over a range of source material and bit-rates.
  • the coded data adheres to the fixed-bit-rate requirements of the ISO/IEC MPEG video coding standard.
  • the additional coder complexity required to implement the adaptive techniques is modest with respect to the basic operations of motion estimation, discrete cosine transforms, quantization, and Huffman coding, which are part of a basic coder.
  • the operation of the QP-adaptive Pre-processor 3 of the invention is based on the observation that, under certain conditions, more visually pleasing images are produced by low bit-rate coders when the input pictures have been pre-processed to attenuate high-frequency information and/or to remove noise, which is inefficient to code, but visually less significant than low-frequency noise-free information.
  • sequences contain regions of non-negligible size which are spatially very complex, or if noise has been introduced for some reason, an inordinate number of bits is required to represent the high-detail regions and noise accurately, leading to an overall degradation in visual quality. This degradation often takes the form of visually distracting, flickering noise-like artifacts.
  • pre-processing such as linear or non-linear filtering, which makes the images look less like the original, but which allows for better rendition of the low-frequency information without distracting artifacts.
  • pre-processing many sequences are such that the visual quality at low bit-rates is quite acceptable without any need to reduce the high-frequency information and noise.
  • pre-processing introduces degradations unnecessarily.
  • quantization level required to code the sequence at the target bit-rate.
  • the main advantage of using information about the quantization factor to control the amount of pre-processing is that it is independent of the bit-rate. Generally speaking, if the quantization level is very high (implying coarse quantization and hence poor quality reconstruction) much of the time, the reason is that the scene is too complex to code accurately at the target bit-rate.
  • QP prev is passed to the QP-Adaptive Pre-processor 3 from the AQ/RC Coder 1. Based on the values of QP prev from possibly more than one prevous picture, one of several pre-processors is selected to be applied to all pictures starting at some point in the future, and continuing until a new value of QP prev from a later picture causes another change in the pre-processor. As seen in Figure 15, the QP prev signal is received in an Implementation Lag Buffer 31 and passed to a Pre-processor Algorithm Selector unit 32 which controls switching of the signal to a Pre-processor unit 33.
  • the Pre-processor unit 33 can consist of a set of filter, Filter 1, Filter 2, ..., Filter n.
  • One preferred implementation of Pre-processor unit 33 is shown in Figure 16 wherein the preprocessor filters are purely linear, and there are three possible filter states ( FS ).
  • T 1 and T sub 2 are 10 and 5, respectively.
  • filters filter states
  • filter state update rule and implementation lag described above represent but one of many possibilities within the scope of the invention. It is contemplated that there can be an arbitrary number of filters, and they can be nonlinear or spatially adaptive. Another important variation is to perform the filter state update more frequently, and to simultaneously reduce the implementation lag. For example, the filter state update can take place after every P-picture, with the implementation lag reduced to the delay between P-pictures.

Claims (7)

  1. Ein Verfahren zum Zuordnen von Bits, die zur Komprimierungscodierung digitaler Datensignale, welche eine oder mehrere Gruppen von Bildern in einer bewegten Videosequenz darstellen, benutzt werden, in Form eines M-PEG II-Datenstroms, bestehend aus folgenden Schritten:
    Identifizieren jedes Bildes der Gruppe bzw. Gruppen, die einer Komprimierungscodierung unterzogen werden soll, als zugehörig zu einem der drei Typen I, P, B;
    Ermitteln der Gesamtanzahl der Bits (Bset), die bei der Komprimierungscodierung jeder Bildergruppe verwendet werden soll, anhand einer festgelegten Soll-Bitrate für jede Sequenz, wobei die Gesamtanzahl der Bits (Bset) gleich einer durchschnittlichen Bitzuordung (Bavg) multipliziert mit der Gesamtanzahl der I-Bilder (nI), P-Bilder (nP) und B-Bilder (nB) in der Gruppe ist, so daß Bset = (nI + nP + nB) · Bavg ist;
    und, nachdem vorzugsweise von der Gesamtanzahl der Bits (Bset) ein Schätzwert (Sset) für die Anzahl der zum Codieren der Nebeninformation in jeder Gruppe benötigten Bits subtrahiert worden ist, woraus eine modifizierte Gesamtanzahl der Bits (Cset) resultiert, von der Gesamtanzahl der Bits (Cset oder Bset) Bits zur Verwendung bei der Komprimierungscodierung eines Bildes in jeder Gruppe zugeordnet werden, indem vor der Komprimierungscodierung der einzelnen Bilder Zuordnungen (CI, CP, CB) für jeden Bildtyp in der Gruppe bestimmt werden, unter Verwendung
    1) des Schwierigkeitsgrades (DI, DP, DB) der Komprimierungscodierung jedes Bildtyps, wobei der Schwierigkeitsgrad der räumlichen Komplexität eines betreffenden Bildes entspricht, so daß die Bitzuordnung (CI, CP, CB) für einen betreffenden Bildtyp mit zunehmendem bzw. abnehmendem Schwierigkeitsgrad (DI, DP, DB) der Komprimierungscodierung zu- bzw. abnimmt, und
    2) der Gesamtanzahlen (NI, NP, NB) jedes der drei Bildtypen in jeder Gruppe zur Erzeugung von Zuordnungen, die die feste Soll-Bitrate erfüllen.
  2. Ein Verfahren nach Anspruch 1, bei dem der Zuordnungsschritt nach folgenden Gleichungen ausgeführt wird Cset = nICI + nPCP + nBCB;
    Figure 00460001
    wobei WP und WB Gewichtungsfaktoren sind, um die Bitzuordnungen von P- und B-Bildern im Vergleich zu den anderen weniger stark zu betonen, und E'r ein durchschnittlicher Bewegungskompensationsfehler ist, der bei der bewegungskompensierten Bildrekonstruktion auftritt.
  3. Ein Verfahren nach Anspruch 1, bei dem die Bitzuordnung für jeden Bildtyp proportional zum Schwierigkeitsgrad der Komprimierungscodierung des betreffenden Bildtyps ist.
  4. Ein Verfahren nach Anspruch 1, bei dem der Schwierigkeitsgrad der Komprimierungscodierung jedes Bildtyps anhand der Schwierigkeit der Komprimierungscodierung der Pixeldaten des zu codierenden Bildes und mindestens eines bereits codierten Bildes aus der Gruppe ermittelt wird.
  5. Ein Verfahren nach Anspruch 1, bei dem der Schwierigkeitsgrad der Komprimierungscodierung jedes Bildtyps anhand der Schwierigkeit der Komprimierungscodierung der Pixeldifferenzdaten des zu codierenden Bildes und mindestens eines bereits codierten Bildes aus der Gruppe ermittelt wird.
  6. Ein System zur Zuordnung von Bits, die zur Komprimierungscodierung digitaler Datensignale, welche eine oder mehrere Gruppen von Bildern in einer bewegten Videosequenz darstellen, benutzt werden, in Form eines M-PEG II-Datenstroms, bestehend aus:
    Mitteln zum Identifizieren jedes Bildes der Gruppe bzw. Gruppen, die einer Komprimierungscodierung unterzogen werden soll, als zugehörig zu einem der drei Typen I, P, B;
    Mitteln 1 - 3 zur Ermittlung der Gesamtanzahl der Bits (Bset), die bei der Komprimierungscodierung jeder Bildergruppe verwendet werden soll, anhand einer festgelegten Soll-Bitrate für jede Sequenz, wobei die Gesamtanzahl der Bits (Bset) gleich einer durchschnittlichen Bitzuordung (Bavg) multipliziert mit der Gesamtanzahl der I-Bilder (nI), P-Bilder (nP) und B-Bilder (nB) in der Gruppe ist, so daß Bset = (nI + nP + nB) · Bavg ist; Mitteln, um vorzugsweise von der Gesamtanzahl der Bits (Bset) einen Schätzwert (Sset) für die Anzahl der zum Codieren der Nebeninformation in jeder Gruppe benötigten Bits zu subtrahieren, woraus eine modifizierte Gesamtanzahl der Bits (Cset) resultiert;
    und Mitteln 2, um aus der Gesamtanzahl der Bits (Cset oder Bset) Bits zur Verwendung bei der Komprimierungscodierung eines Bildes in jeder Gruppe zuzuordnen, indem vor der Komprimierungscodierung der einzelnen Bilder Zuordnungen (CI, CP, CB) für jeden Bildtyp in der Gruppe bestimmt werden, unter Verwendung
    1) des Schwierigkeitsgrades (DI, DP, DB) der Komprimierungscodierung jedes Bildtyps, wobei der Schwierigkeitsgrad der räumlichen Komplexität eines betreffenden Bildes entspricht, so daß die Bitzuordnung (CI, CP, CB) für einen betreffenden Bildtyp mit zunehmendem bzw. abnehmendem Schwierigkeitsgrad (DI, DP, DB) der Komprimierungscodierung zu- bzw. abnimmt, und
    2) der Gesamtanzahlen (NI, NP, NB) jedes der drei Bildtypen in jeder Gruppe zur Erzeugung von Zuordnungen, die die feste Soll-Bitrate erfüllen.
  7. Ein System nach Anspruch 6, bei dem das Zuordnungsmittel 2 folgende Gleichungen erfüllt: Cset = nICI + nPCP + nBCB;
    Figure 00490001
    wobei WP und WB Gewichtungsfaktoren sind, um die Bitzuordnungen von P- und B-Bildern im Vergleich zu den anderen weniger stark zu betonen, und E'r ein durchschnittlicher Bewegungskompensationsfehler ist, der bei der bewegungskompensierten Bildrekonstruktion auftritt.
EP92118193A 1991-11-08 1992-10-23 Verfahren und Einrichtung zur Kompression von sich bewegenden Videobildern mit adaptiver Bitzuordnung und Quantisierung Expired - Lifetime EP0540961B1 (de)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7889792B2 (en) 2003-12-24 2011-02-15 Apple Inc. Method and system for video encoding using a variable number of B frames

Families Citing this family (322)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9405914D0 (en) * 1994-03-24 1994-05-11 Discovision Ass Video decompression
EP0576749B1 (de) 1992-06-30 1999-06-02 Discovision Associates Datenpipelinesystem
US5317397A (en) * 1991-05-31 1994-05-31 Kabushiki Kaisha Toshiba Predictive coding using spatial-temporal filtering and plural motion vectors
US6005627A (en) * 1991-05-31 1999-12-21 Kabushiki Kaisha Toshiba Video coding apparatus
US5986713A (en) * 1991-05-31 1999-11-16 Kabushiki Kaisha Toshiba Video coding apparatus using inter-field prediction
JP3189861B2 (ja) * 1992-11-13 2001-07-16 ソニー株式会社 動画像符号化装置および方法
US5640208A (en) * 1991-06-27 1997-06-17 Sony Corporation Video signal encoding in accordance with stored parameters
US5539836A (en) * 1991-12-20 1996-07-23 Alaris Inc. Method and apparatus for the realization of two-dimensional discrete cosine transform for an 8*8 image fragment
US6870884B1 (en) * 1992-01-29 2005-03-22 Mitsubishi Denki Kabushiki Kaisha High-efficiency encoder and video information recording/reproducing apparatus
EP1555817B1 (de) * 1992-01-29 2008-07-23 Mitsubishi Denki Kabushiki Kaisha Kodiergerät mit hoher Wirksamkeit und Vorrichtung zum Aufzeichnen/Wiedergeben von Videoinformation
JP3134455B2 (ja) * 1992-01-29 2001-02-13 ソニー株式会社 高能率符号化装置及び方法
JPH05236427A (ja) * 1992-02-25 1993-09-10 Sony Corp 画像信号の符号化装置及び符号化方法
JPH05268590A (ja) * 1992-03-17 1993-10-15 Nec Corp 動画像符号化復号化回路
KR0150955B1 (ko) * 1992-05-27 1998-10-15 강진구 비트고정을 위한 영상압축방법과 신장방법 및 그 장치
US5291281A (en) * 1992-06-18 1994-03-01 General Instrument Corporation Adaptive coding level control for video compression systems
US5289276A (en) * 1992-06-19 1994-02-22 General Electric Company Method and apparatus for conveying compressed video data over a noisy communication channel
US5768561A (en) 1992-06-30 1998-06-16 Discovision Associates Tokens-based adaptive video processing arrangement
US6079009A (en) 1992-06-30 2000-06-20 Discovision Associates Coding standard token in a system compromising a plurality of pipeline stages
US6330665B1 (en) 1992-06-30 2001-12-11 Discovision Associates Video parser
US5809270A (en) 1992-06-30 1998-09-15 Discovision Associates Inverse quantizer
US6047112A (en) 1992-06-30 2000-04-04 Discovision Associates Technique for initiating processing of a data stream of encoded video information
US6263422B1 (en) 1992-06-30 2001-07-17 Discovision Associates Pipeline processing machine with interactive stages operable in response to tokens and system and methods relating thereto
US6112017A (en) 1992-06-30 2000-08-29 Discovision Associates Pipeline processing machine having a plurality of reconfigurable processing stages interconnected by a two-wire interface bus
US5784631A (en) 1992-06-30 1998-07-21 Discovision Associates Huffman decoder
US6067417A (en) 1992-06-30 2000-05-23 Discovision Associates Picture start token
JP3127600B2 (ja) * 1992-09-11 2001-01-29 ソニー株式会社 ディジタル信号復号化装置及び方法
US5379122A (en) * 1992-10-02 1995-01-03 Xerox Corporation Decompression of standard ADCT-compressed images
US5384598A (en) * 1992-10-20 1995-01-24 International Business Machines Corporation System and method for frame differencing video compression and decompression with frame rate scalability
JP3343962B2 (ja) * 1992-11-11 2002-11-11 ソニー株式会社 高能率符号化方法及び装置
EP0670096A4 (de) * 1992-11-16 1996-03-27 Multimedia Systems Corp Methode zur herstellung und übertragung von verbesserten interaktiven multimedia-information.
JP3240017B2 (ja) * 1993-01-11 2001-12-17 ソニー株式会社 Ｍｐｅｇ信号記録方法およびｍｐｅｇ信号再生方法
JP3282260B2 (ja) * 1993-01-18 2002-05-13 ソニー株式会社 画像再生装置及び方法
US5786858A (en) * 1993-01-19 1998-07-28 Sony Corporation Method of encoding image signal, apparatus for encoding image signal, method of decoding image signal, apparatus for decoding image signal, and image signal recording medium
EP0645930B1 (de) * 1993-04-09 2000-06-14 Sony Corporation Verfahren und vorrichtung zur bildkodierung
US5703646A (en) * 1993-04-09 1997-12-30 Sony Corporation Picture encoding method, picture encoding apparatus and picture recording medium
KR970000683B1 (ko) * 1993-05-31 1997-01-16 삼성전자 주식회사 해상도 가변 적응적 화상압축/복원방법 및 장치
FR2707070B1 (de) * 1993-06-22 1995-09-08 Centre Nat Etd Spatiales
US5861894A (en) 1993-06-24 1999-01-19 Discovision Associates Buffer manager
US5805914A (en) 1993-06-24 1998-09-08 Discovision Associates Data pipeline system and data encoding method
US5699544A (en) * 1993-06-24 1997-12-16 Discovision Associates Method and apparatus for using a fixed width word for addressing variable width data
US5829007A (en) * 1993-06-24 1998-10-27 Discovision Associates Technique for implementing a swing buffer in a memory array
US5812735A (en) * 1993-07-09 1998-09-22 Sony Corporaiton Picture signal decoding method and picture signal decoding apparatus
FR2708168B1 (fr) * 1993-07-20 1995-08-25 Thomson Consumer Electronics Procédé et dispositif d'estimation d'un budget de bits pour encodeurs à longueur de mot variable.
US5598514A (en) * 1993-08-09 1997-01-28 C-Cube Microsystems Structure and method for a multistandard video encoder/decoder
JP2531106B2 (ja) * 1993-08-17 1996-09-04 日本電気株式会社 動画像符号化制御方式
FR2711879B1 (fr) * 1993-10-22 1995-12-15 Thomson Csf Procédé et dispositif de codage inter-trame avec régulation de débit pour l'enregistrement d'images sur magnétoscope.
KR970003789B1 (ko) * 1993-11-09 1997-03-21 한국전기통신공사 비디오 부호기의 전송율을 제어하기 위한 비트 할당 방법
BE1007807A3 (nl) * 1993-11-30 1995-10-24 Philips Electronics Nv Inrichting voor het coderen van een videosignaal.
BE1007808A3 (nl) * 1993-11-30 1995-10-24 Philips Electronics Nv Inrichting voor het coderen van een videosignaal.
JPH07202820A (ja) * 1993-12-28 1995-08-04 Matsushita Electric Ind Co Ltd ビットレート制御システム
US5764698A (en) * 1993-12-30 1998-06-09 International Business Machines Corporation Method and apparatus for efficient compression of high quality digital audio
US5587708A (en) * 1994-01-19 1996-12-24 Industrial Technology Research Institute Division technique unified quantizer-dequantizer
US5592226A (en) * 1994-01-26 1997-01-07 Btg Usa Inc. Method and apparatus for video data compression using temporally adaptive motion interpolation
EP0670663A1 (de) * 1994-03-02 1995-09-06 Laboratoires D'electronique Philips S.A.S. Verfahren und Vorrichtung zur Kodierung von eine Bildsequenz darstellenden digitalen signalen
FR2717029A1 (fr) * 1994-03-02 1995-09-08 Philips Laboratoire Electroniq Procédé et dispositif de codage à longueur variable de signaux numériques.
US5563961A (en) * 1994-03-03 1996-10-08 Radius Inc. Video data compression method and system which measures compressed data storage time to optimize compression rate
US5576765A (en) * 1994-03-17 1996-11-19 International Business Machines, Corporation Video decoder
CA2145365C (en) * 1994-03-24 1999-04-27 Anthony M. Jones Method for accessing banks of dram
CA2145361C (en) 1994-03-24 1999-09-07 Martin William Sotheran Buffer manager
CA2145379C (en) * 1994-03-24 1999-06-08 William P. Robbins Method and apparatus for addressing memory
US5754235A (en) * 1994-03-25 1998-05-19 Sanyo Electric Co., Ltd. Bit-rate conversion circuit for a compressed motion video bitstream
DE69536095D1 (de) * 1994-03-25 2010-09-30 Nec Corp Bildwiedergabevorrichtung
US5541852A (en) * 1994-04-14 1996-07-30 Motorola, Inc. Device, method and system for variable bit-rate packet video communications
JP3265818B2 (ja) * 1994-04-14 2002-03-18 松下電器産業株式会社 動画符号化方法
CN1067203C (zh) * 1994-04-20 2001-06-13 汤姆森消费电子有限公司 利用恒定位率编码器的多路复用系统
KR100314329B1 (ko) * 1994-04-20 2001-12-28 크리트먼 어윈 엠 일정비트율엔코더를이용하는멀티플렉서
US6055270A (en) * 1994-04-20 2000-04-25 Thomson Cosumer Electronics, Inc. Multiplexer system using constant bit rate encoders
US5650829A (en) * 1994-04-21 1997-07-22 Sanyo Electric Co., Ltd. Motion video coding systems with motion vector detection
DE4416967A1 (de) * 1994-05-13 1995-11-16 Thomson Brandt Gmbh Verfahren und Vorrichtung zur Transcodierung von Bitströmen mit Videodaten
FR2720582B1 (fr) * 1994-05-27 1996-08-14 Sgs Thomson Microelectronics Circuit de détermination du coefficient de quantification dans une chaîne de compression d'image.
FR2721787B1 (fr) * 1994-06-22 1996-07-26 Thomson Consumer Electronics Procédé de quantification des coefficients.
US5767898A (en) * 1994-06-23 1998-06-16 Sanyo Electric Co., Ltd. Three-dimensional image coding by merger of left and right images
JP3050047B2 (ja) * 1994-06-24 2000-06-05 日本ビクター株式会社 動画像符号化装置及び動画像符号化方法
US5651078A (en) * 1994-07-18 1997-07-22 Thomson Consumer Electronics, Inc. Method and apparatus for reducing contouring in video compression
JP3336754B2 (ja) * 1994-08-19 2002-10-21 ソニー株式会社 デジタルビデオ信号の記録方法及び記録装置
JP2882287B2 (ja) * 1994-08-22 1999-04-12 日本電気株式会社 動画像符号化装置
GB9417138D0 (en) 1994-08-23 1994-10-12 Discovision Ass Data rate conversion
JP3911035B2 (ja) * 1994-08-31 2007-05-09 ソニー株式会社 動画像符号化方法及び動画像符号化装置
JPH08154247A (ja) * 1994-09-29 1996-06-11 Sanyo Electric Co Ltd 圧縮画像データ処理装置及び方法
JP3954656B2 (ja) * 1994-09-29 2007-08-08 ソニー株式会社 画像符号化装置及び方法
JP3711572B2 (ja) * 1994-09-30 2005-11-02 ソニー株式会社 画像符号化装置及び方法
US5734419A (en) 1994-10-21 1998-03-31 Lucent Technologies Inc. Method of encoder control
CA2157066C (en) 1994-10-21 1999-09-21 Nelson Botsford Iii Method for controlling a compressed data buffer
US5889561A (en) * 1994-11-04 1999-03-30 Rca Thomson Licensing Corporation Method and apparatus for scaling a compressed video bitstream
GB9424436D0 (en) * 1994-12-02 1995-01-18 Philips Electronics Video editing buffer management
JPH08163554A (ja) * 1994-12-02 1996-06-21 Electron & Telecommun Res Inst ビデオビット率制御方法
US5646687A (en) * 1994-12-29 1997-07-08 Lucent Technologies Inc. Temporally-pipelined predictive encoder/decoder circuit and method
US5710595A (en) * 1994-12-29 1998-01-20 Lucent Technologies Inc. Method and apparatus for controlling quantization and buffering for digital signal compression
EP0720376B1 (de) * 1994-12-29 2001-10-31 Sony Corporation Einrichtung und Verfahren zur Quantisierung
US5802211A (en) * 1994-12-30 1998-09-01 Harris Corporation Method and apparatus for transmitting and utilizing analog encoded information
FR2729520B1 (fr) * 1995-01-16 1997-06-13 France Telecom Procede de regulation du debit de codage par prediction temporelle et compensation de mouvement, d'un signal numerique de television
US5546336A (en) * 1995-01-19 1996-08-13 International Business Machine Corporation Processor using folded array structures for transposition memory and fast cosine transform computation
US5677969A (en) * 1995-02-23 1997-10-14 Motorola, Inc. Method, rate controller, and system for preventing overflow and underflow of a decoder buffer in a video compression system
JPH08242452A (ja) * 1995-03-02 1996-09-17 Matsushita Electric Ind Co Ltd 映像信号圧縮符号化装置
US5841476A (en) * 1995-03-03 1998-11-24 Kokusai Denshin Denwa Co. Ltd. Coding apparatus for encoding motion picture
US5734677A (en) * 1995-03-15 1998-03-31 The Chinese University Of Hong Kong Method for compression of loss-tolerant video image data from multiple sources
JPH08256341A (ja) * 1995-03-17 1996-10-01 Sony Corp 画像信号符号化方法、画像信号符号化装置、画像信号記録媒体、及び画像信号復号化装置
US6198767B1 (en) * 1995-03-27 2001-03-06 International Business Machines Corporation Apparatus for color component compression
US5668598A (en) * 1995-03-27 1997-09-16 International Business Machines Corporation Motion video compression system with guaranteed bit production limits
JP2809126B2 (ja) * 1995-03-30 1998-10-08 日本電気株式会社 音声信号処理回路および音声信号処理方法
US5729294A (en) * 1995-04-05 1998-03-17 International Business Machines Corporation Motion video compression system with novel adaptive quantization
US5694170A (en) * 1995-04-06 1997-12-02 International Business Machines Corporation Video compression using multiple computing agents
US5914712A (en) * 1995-05-08 1999-06-22 Video Jukebox Network, Inc. Interactive video system
US5819004A (en) * 1995-05-08 1998-10-06 Kabushiki Kaisha Toshiba Method and system for a user to manually alter the quality of previously encoded video frames
US5623424A (en) * 1995-05-08 1997-04-22 Kabushiki Kaisha Toshiba Rate-controlled digital video editing method and system which controls bit allocation of a video encoder by varying quantization levels
US5612900A (en) * 1995-05-08 1997-03-18 Kabushiki Kaisha Toshiba Video encoding method and system which encodes using a rate-quantizer model
GB2301970B (en) * 1995-06-06 2000-03-01 Sony Uk Ltd Motion compensated video processing
US6480664B1 (en) * 1995-06-07 2002-11-12 Hou-Chun Ting Trick mode VTR which generates trick play data from a stream of images containing intra-pictures and predictive pictures and selects specific DCT coefficients for intra-pictures
US5860086A (en) * 1995-06-07 1999-01-12 International Business Machines Corporation Video processor with serialization FIFO
KR0153671B1 (ko) * 1995-06-30 1998-11-16 배순훈 고선명 텔레비젼 엔코더의 레이트 콘트롤러
FR2736743B1 (fr) * 1995-07-10 1997-09-12 France Telecom Procede de controle de debit de sortie d'un codeur de donnees numeriques representatives de sequences d'images
JP2795223B2 (ja) * 1995-07-18 1998-09-10 日本電気株式会社 画像信号の符号化方法
EP0757490A3 (de) 1995-08-02 1999-01-13 Matsushita Electric Industrial Co., Ltd. Videokodierungsvorrichtung und ihre Anwendung in ein Videoübertragungssystem, Quantisierungskontrollverfahren und zugehöriges Verfahren zur Rechnung des durchschnittlichen Datenflusses
JPH0955941A (ja) * 1995-08-16 1997-02-25 Sony Corp 画像符号化方法、画像符号化装置、及び画像符号化データの記録装置
US5910909A (en) * 1995-08-28 1999-06-08 C-Cube Microsystems, Inc. Non-linear digital filters for interlaced video signals and method thereof
JPH0974566A (ja) * 1995-09-04 1997-03-18 Sony Corp 圧縮符号化装置及び圧縮符号化データの記録装置
US5652629A (en) * 1995-09-12 1997-07-29 International Business Machines Corporation Bidirectional motion estimation in a motion video compression system
GB9519923D0 (en) * 1995-09-29 1995-11-29 Philips Electronics Nv Motion estimation for predictive image coding
US5675384A (en) * 1995-10-03 1997-10-07 Nec Usa, Inc. VBR MPEG video encoding for ATM networks with dynamic bandwidth renegotiation
US6160846A (en) * 1995-10-25 2000-12-12 Sarnoff Corporation Apparatus and method for optimizing the rate control in a coding system
US6571019B1 (en) * 1995-10-26 2003-05-27 Hyundai Curitel, Inc Apparatus and method of encoding/decoding a coded block pattern
US6192081B1 (en) 1995-10-26 2001-02-20 Sarnoff Corporation Apparatus and method for selecting a coding mode in a block-based coding system
GB2306831B (en) * 1995-10-30 2000-05-24 Sony Uk Ltd Video data compression
WO1997016926A1 (en) * 1995-10-31 1997-05-09 Sarnoff Corporation Method and apparatus for determining ambient conditions from an image sequence
KR100355375B1 (ko) * 1995-11-01 2002-12-26 삼성전자 주식회사 영상부호화장치에있어서양자화간격결정방법및회로
DE69615533T2 (de) * 1995-11-15 2002-05-23 Koninkl Philips Electronics Nv Verfahren und vorrichtung zur steuerung der globalen bitrate einer vielzahl von kodierern
US5717464A (en) * 1995-12-18 1998-02-10 Divicom, Inc. Rate control for a video encoder
US5761398A (en) * 1995-12-26 1998-06-02 C-Cube Microsystems Inc. Three stage hierarchal motion vector determination
US5872598A (en) * 1995-12-26 1999-02-16 C-Cube Microsystems Scene change detection using quantization scale factor rate control
US5686963A (en) * 1995-12-26 1997-11-11 C-Cube Microsystems Method for performing rate control in a video encoder which provides a bit budget for each frame while employing virtual buffers and virtual buffer verifiers
US5801779A (en) * 1995-12-26 1998-09-01 C-Cube Microsystems, Inc. Rate control with panic mode
US6057893A (en) * 1995-12-28 2000-05-02 Sony Corporation Picture encoding method, picture encoding apparatus, picture transmitting method and picture recording medium
KR970057947A (ko) * 1995-12-28 1997-07-31 배순훈 영상 부호화기에서의 타입 결정 및 버퍼 제어 장치
US5963256A (en) * 1996-01-11 1999-10-05 Sony Corporation Coding according to degree of coding difficulty in conformity with a target bit rate
US5719632A (en) * 1996-01-25 1998-02-17 Ibm Corporation Motion video compression system with buffer empty/fill look-ahead bit allocation
KR0170735B1 (ko) * 1996-01-29 1999-03-20 김광호 정지영상 데이터의 압축장치
US6957350B1 (en) 1996-01-30 2005-10-18 Dolby Laboratories Licensing Corporation Encrypted and watermarked temporal and resolution layering in advanced television
US5731839A (en) * 1996-02-06 1998-03-24 David Sarnoff Research Center, Inc. Bitstream for evaluating predictive video decoders and a method of generating same
US5731835A (en) * 1996-02-26 1998-03-24 David Sarnoff Research Center, Inc. Dynamic coding rate control in a block-based video coding system
JP3493872B2 (ja) * 1996-02-29 2004-02-03 ソニー株式会社 画像データ処理方法およびその装置
US6100931A (en) * 1996-03-19 2000-08-08 Sony Corporation Method and apparatus for controlling a target amount of code and for compressing video data
US5844607A (en) * 1996-04-03 1998-12-01 International Business Machines Corporation Method and apparatus for scene change detection in digital video compression
DE69738878D1 (de) * 1996-04-12 2008-09-11 Sony Corp Bildkodierung mit Pufferunterlaufvermeidung
EP1182888A3 (de) * 1996-04-25 2004-11-03 Matsushita Electric Industrial Co., Ltd. Videokodierung mit bitratenabhängiger Quantisierung
FR2748623B1 (fr) 1996-05-09 1998-11-27 Thomson Multimedia Sa Encodeur a debit variable
US6101276A (en) * 1996-06-21 2000-08-08 Compaq Computer Corporation Method and apparatus for performing two pass quality video compression through pipelining and buffer management
US6026217A (en) * 1996-06-21 2000-02-15 Digital Equipment Corporation Method and apparatus for eliminating the transpose buffer during a decomposed forward or inverse 2-dimensional discrete cosine transform through operand decomposition storage and retrieval
US6292589B1 (en) * 1996-06-21 2001-09-18 Compaq Computer Corporation Method for choosing rate control parameters in motion-compensated transform-based picture coding scheme using non-parametric technique
US5805228A (en) * 1996-08-09 1998-09-08 U.S. Robotics Access Corp. Video encoder/decoder system
US6337879B1 (en) * 1996-08-14 2002-01-08 Sony Corporation Video data compression apparatus and method of same
US6205253B1 (en) 1996-08-19 2001-03-20 Harris Corporation Method and apparatus for transmitting and utilizing analog encoded information
JP3318825B2 (ja) * 1996-08-20 2002-08-26 ソニー株式会社 デジタル信号符号化処理方法、デジタル信号符号化処理装置、デジタル信号記録方法、デジタル信号記録装置、記録媒体、デジタル信号伝送方法及びデジタル信号伝送装置
JP3908789B2 (ja) * 1996-08-30 2007-04-25 コーニンクレッカ、フィリップス、エレクトロニクス、エヌ．ヴィ． ビデオ伝送システム
JP3864461B2 (ja) * 1996-08-30 2006-12-27 ソニー株式会社 映像データ圧縮装置およびその方法
FR2753330B1 (fr) * 1996-09-06 1998-11-27 Thomson Multimedia Sa Procede de quantification pour codage video
KR100297830B1 (ko) * 1996-11-09 2001-08-07 윤종용 영상단위별 비트발생량 조절 장치 및 방법
US6094455A (en) * 1996-09-25 2000-07-25 Matsushita Electric Industrial Co., Ltd. Image compression/encoding apparatus and system with quantization width control based on bit generation error
US5818535A (en) * 1996-09-30 1998-10-06 Alaris, Inc. Method and apparatus for adaptive hybrid motion video compression and decompression
US5745058A (en) * 1996-10-21 1998-04-28 International Business Machines Corporation Method and system for compressing microcode to be executed within a data processing system
US6037985A (en) * 1996-10-31 2000-03-14 Texas Instruments Incorporated Video compression
DE69630122T2 (de) * 1996-11-04 2004-05-27 Alcatel Verfahren und Vorrichtung zur Vorfilterung von Videobildern
US6512775B1 (en) * 1996-11-08 2003-01-28 The Trustees Of Columbia University In The City Of New York Method and apparatus for a programmable bitstream parser for audiovisual and generic decoding systems
JPH10145773A (ja) * 1996-11-14 1998-05-29 Toshiba Corp 動画像データの暗号化方法およびその方法が適用されるコンピュータシステム並びに動画像データ符号化／復号化装置
US6243417B1 (en) * 1996-12-12 2001-06-05 Sony Corporation Device and method for encoding image data, and image data transmission method
WO1998037701A1 (en) 1997-02-12 1998-08-27 Sarnoff Corporation Apparatus and method for optimizing the rate control in a coding system
US6272175B1 (en) * 1997-02-13 2001-08-07 Conexant Systems, Inc. Video signal coding systems and processes using adaptive quantization
EP1359766A3 (de) * 1997-02-14 2005-02-16 AT&T Corp. Verfahren zur Erzeugung eines dequantizierten DC-Luminanz oder DC-Chrominanz Koeffizienten
US6347116B1 (en) * 1997-02-14 2002-02-12 At&T Corp. Non-linear quantizer for video coding
US7269219B1 (en) 1997-02-14 2007-09-11 At&T Corp. Non-linear quantizer for video coding
US6577680B2 (en) * 1997-03-12 2003-06-10 Matsushita Electric Industrial Co., Ltd. Video signal coding method and coding device adapted to control code amounts according to the characteristics of pictures
US6553068B1 (en) * 1997-03-12 2003-04-22 Matsushita Electric Industrial Co., Ltd. Video signal coding method and device adapted to control code amounts according to the characteristics of pictures
US6178203B1 (en) * 1997-04-03 2001-01-23 Lsi Logic Corporation Method and apparatus for two-row decoding of MPEG video
US6067321A (en) * 1997-04-03 2000-05-23 Lsi Logic Corporation Method and apparatus for two-row macroblock decoding to improve caching efficiency
JP4061511B2 (ja) * 1997-04-15 2008-03-19 ソニー株式会社 符号化装置及び符号化方法
JP3588970B2 (ja) * 1997-04-30 2004-11-17 ソニー株式会社 信号符号化方法、信号符号化装置、信号記録媒体及び信号伝送方法
US6088392A (en) * 1997-05-30 2000-07-11 Lucent Technologies Inc. Bit rate coder for differential quantization
US6339616B1 (en) 1997-05-30 2002-01-15 Alaris, Inc. Method and apparatus for compression and decompression of still and motion video data based on adaptive pixel-by-pixel processing and adaptive variable length coding
WO1999003282A1 (en) 1997-07-08 1999-01-21 Sony Corporation Video data encoder, video data encoding method, video data transmitter, and video data recording medium
US6023296A (en) * 1997-07-10 2000-02-08 Sarnoff Corporation Apparatus and method for object based rate control in a coding system
US6690833B1 (en) 1997-07-14 2004-02-10 Sarnoff Corporation Apparatus and method for macroblock based rate control in a coding system
US6192075B1 (en) * 1997-08-21 2001-02-20 Stream Machine Company Single-pass variable bit-rate control for digital video coding
FR2769453B1 (fr) * 1997-10-06 2000-01-07 Telediffusion Fse Procede d'evaluation de la degradation d'une image video introduite par un systeme de codage et/ou de stockage et/ou de transmission numerique
US6885702B1 (en) 1997-10-06 2005-04-26 Telediffusion De France Method for spatial synchronization of a digitally coded video image and/or for identification of the syntax of a video sequence
US5978029A (en) * 1997-10-10 1999-11-02 International Business Machines Corporation Real-time encoding of video sequence employing two encoders and statistical analysis
US6366704B1 (en) 1997-12-01 2002-04-02 Sharp Laboratories Of America, Inc. Method and apparatus for a delay-adaptive rate control scheme for the frame layer
US6111914A (en) * 1997-12-01 2000-08-29 Conexant Systems, Inc. Adaptive entropy coding in adaptive quantization framework for video signal coding systems and processes
US6118822A (en) * 1997-12-01 2000-09-12 Conexant Systems, Inc. Adaptive entropy coding in adaptive quantization framework for video signal coding systems and processes
WO1999030505A1 (en) * 1997-12-08 1999-06-17 Sony Corporation Encoder and encoding method
GB2337392B (en) * 1997-12-08 2002-04-17 Sony Corp Coding device and method
US6067118A (en) * 1997-12-16 2000-05-23 Philips Electronics North America Corp. Method of frame-by-frame calculation of quantization matrices
US6181742B1 (en) * 1998-01-26 2001-01-30 International Business Machines Corporation Single pass target allocation for video encoding
US6192154B1 (en) * 1998-01-26 2001-02-20 International Business Machines Corporation Two-pass encoding method of digital motion video sequences for constant-or variable bit rate
US6459439B1 (en) * 1998-03-09 2002-10-01 Macromedia, Inc. Reshaping of paths without respect to control points
US6278735B1 (en) 1998-03-19 2001-08-21 International Business Machines Corporation Real-time single pass variable bit rate control strategy and encoder
US6895048B2 (en) * 1998-03-20 2005-05-17 International Business Machines Corporation Adaptive encoding of a sequence of still frames or partially still frames within motion video
JP2002506605A (ja) * 1998-04-30 2002-02-26 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ データ圧縮
US6125147A (en) * 1998-05-07 2000-09-26 Motorola, Inc. Method and apparatus for reducing breathing artifacts in compressed video
US6212232B1 (en) 1998-06-18 2001-04-03 Compaq Computer Corporation Rate control and bit allocation for low bit rate video communication applications
US6804294B1 (en) * 1998-08-11 2004-10-12 Lucent Technologies Inc. Method and apparatus for video frame selection for improved coding quality at low bit-rates
DE59904186D1 (de) 1998-09-29 2003-03-06 Siemens Ag Verfahren und anordnung zur bearbeitung eines digitalisierten bildes mit bildpunkten
CN1174624C (zh) * 1998-09-29 2004-11-03 松下电器产业株式会社 可变比特率编码装置
WO2000040032A1 (en) * 1998-12-23 2000-07-06 Koninklijke Philips Electronics N.V. Adaptive buffer and quantizer regulation scheme for bandwidth scalability of video data
CN1184820C (zh) * 1999-01-15 2005-01-12 皇家菲利浦电子有限公司 编码和噪声过滤图象序列
JP2000253397A (ja) * 1999-03-01 2000-09-14 Nec Corp 動画像符号化装置
FR2791211B1 (fr) 1999-03-18 2001-10-19 Cit Alcatel Dispositif de regulation en debit ou en qualite d'un compresseur de donnees numeriques, notamment d'images
KR100390115B1 (ko) * 1999-04-12 2003-07-04 마츠시타 덴끼 산교 가부시키가이샤 화상 처리 방법, 화상 처리 장치 및 데이터 기억 매체
US6633673B1 (en) * 1999-06-17 2003-10-14 Hewlett-Packard Development Company, L.P. Fast fade operation on MPEG video or other compressed data
JP3807157B2 (ja) * 1999-06-25 2006-08-09 日本ビクター株式会社 符号化装置及び符号化方法
JP2001086512A (ja) * 1999-09-14 2001-03-30 Nec Corp 可変ビットレート符号化装置
EP1085765A3 (de) * 1999-09-20 2006-03-01 Matsushita Electric Industrial Co., Ltd. Vorrichtung zur Erzeugung eines Systemstroms, welches die Systemzeitreferenz aufgrund der Anzahl der innerhalb eines bestimmten Zeitraums zu speichernden und dekodierenden Bildern verändert
GB2356510B (en) * 1999-11-18 2004-04-21 Sony Uk Ltd Data compression
US6754371B1 (en) * 1999-12-07 2004-06-22 Sony Corporation Method and apparatus for past and future motion classification
US6810082B1 (en) * 1999-12-17 2004-10-26 Koninklijke Philips Electronics N.V. Chroma based adaptive signal peaking
US6678332B1 (en) 2000-01-04 2004-01-13 Emc Corporation Seamless splicing of encoded MPEG video and audio
US6792047B1 (en) 2000-01-04 2004-09-14 Emc Corporation Real time processing and streaming of spliced encoded MPEG video and associated audio
US7096481B1 (en) 2000-01-04 2006-08-22 Emc Corporation Preparation of metadata for splicing of encoded MPEG video and audio
FI116819B (fi) * 2000-01-21 2006-02-28 Nokia Corp Menetelmä kuvien lähettämiseksi ja kuvakooderi
US6600836B1 (en) * 2000-01-28 2003-07-29 Qualcomm, Incorporated Quality based image compression
US6522693B1 (en) 2000-02-23 2003-02-18 International Business Machines Corporation System and method for reencoding segments of buffer constrained video streams
AU777595B2 (en) * 2000-03-13 2004-10-21 Sony Corporation Content supplying apparatus and method, and recording medium
US6382331B1 (en) * 2000-04-17 2002-05-07 Noble Drilling Services, Inc. Method of and system for optimizing rate of penetration based upon control variable correlation
US7091985B1 (en) 2000-05-16 2006-08-15 International Business Machines Corporation System and method for compressing color data using expandable color palette
JP2002077917A (ja) * 2000-06-13 2002-03-15 Sony Corp 画像データ処理装置及び画像データ処理方法
KR100341063B1 (ko) * 2000-06-28 2002-06-20 송문섭 실시간 영상 통신을 위한 율제어 장치 및 그 방법
US6871006B1 (en) 2000-06-30 2005-03-22 Emc Corporation Processing of MPEG encoded video for trick mode operation
US6771703B1 (en) 2000-06-30 2004-08-03 Emc Corporation Efficient scaling of nonscalable MPEG-2 Video
US7020205B1 (en) * 2000-07-12 2006-03-28 Thomson Licensing Sending progressive video sequences suitable for MPEG and other data formats
US7424058B1 (en) * 2000-09-28 2008-09-09 Autodesk, Inc. Variable bit-rate encoding
US7751683B1 (en) 2000-11-10 2010-07-06 International Business Machines Corporation Scene change marking for thumbnail extraction
US7023924B1 (en) 2000-12-28 2006-04-04 Emc Corporation Method of pausing an MPEG coded video stream
US6937770B1 (en) 2000-12-28 2005-08-30 Emc Corporation Adaptive bit rate control for rate reduction of MPEG coded video
US8374237B2 (en) 2001-03-02 2013-02-12 Dolby Laboratories Licensing Corporation High precision encoding and decoding of video images
US6831947B2 (en) 2001-03-23 2004-12-14 Sharp Laboratories Of America, Inc. Adaptive quantization based on bit rate prediction and prediction error energy
US6907081B2 (en) * 2001-03-30 2005-06-14 Emc Corporation MPEG encoder control protocol for on-line encoding and MPEG data storage
CN1229774C (zh) * 2001-04-09 2005-11-30 皇家菲利浦电子有限公司 有特殊步长适应的自适应差分脉码调制语音编码系统
ES2261637T3 (es) * 2001-04-09 2006-11-16 Koninklijke Philips Electronics N.V. Sistema de codificacion del habla adpcm, con filtros de difuminado de fase y difuminado de fase inverso.
US7174561B2 (en) * 2001-04-13 2007-02-06 Emc Corporation MPEG dual-channel decoder data and control protocols for real-time video streaming
US9894379B2 (en) * 2001-07-10 2018-02-13 The Directv Group, Inc. System and methodology for video compression
US7266150B2 (en) 2001-07-11 2007-09-04 Dolby Laboratories, Inc. Interpolation of video compression frames
US8111754B1 (en) 2001-07-11 2012-02-07 Dolby Laboratories Licensing Corporation Interpolation of video compression frames
US20030112863A1 (en) 2001-07-12 2003-06-19 Demos Gary A. Method and system for improving compressed image chroma information
US6914936B1 (en) * 2001-07-19 2005-07-05 Bigband Networks, Inc. Method for allocating media unit sequences among a plurality of output channels
US6980594B2 (en) 2001-09-11 2005-12-27 Emc Corporation Generation of MPEG slow motion playout
US6968091B2 (en) * 2001-09-18 2005-11-22 Emc Corporation Insertion of noise for reduction in the number of bits for variable-length coding of (run, level) pairs
US6959116B2 (en) * 2001-09-18 2005-10-25 Emc Corporation Largest magnitude indices selection for (run, level) encoding of a block coded picture
US20030099294A1 (en) * 2001-11-27 2003-05-29 Limin Wang Picture level adaptive frame/field coding for digital video content
US6980596B2 (en) * 2001-11-27 2005-12-27 General Instrument Corporation Macroblock level adaptive frame/field coding for digital video content
EP2302929B1 (de) * 2001-11-27 2015-03-25 Samsung Electronics Co., Ltd. Kodierung und Dekodierung eines Bitstroms mit Koordinateninterpolator
US6763068B2 (en) * 2001-12-28 2004-07-13 Nokia Corporation Method and apparatus for selecting macroblock quantization parameters in a video encoder
KR100468726B1 (ko) * 2002-04-18 2005-01-29 삼성전자주식회사 실시간 가변 비트율 제어를 수행하는 부호화 장치 및 방법
WO2004025943A2 (en) * 2002-04-23 2004-03-25 Nokia Corporation Method and device for indicating quantizer parameters in a video coding system
US20030202780A1 (en) * 2002-04-25 2003-10-30 Dumm Matthew Brian Method and system for enhancing the playback of video frames
US7280700B2 (en) * 2002-07-05 2007-10-09 Microsoft Corporation Optimization techniques for data compression
KR20040007818A (ko) * 2002-07-11 2004-01-28 삼성전자주식회사 동영상 부호화를 위한 ｄｃｔ연산량 조절 방법 및 그 장치
US7418037B1 (en) * 2002-07-15 2008-08-26 Apple Inc. Method of performing rate control for a compression system
US7769084B1 (en) 2002-07-15 2010-08-03 Apple Inc. Method for implementing a quantizer in a multimedia compression and encoding system
US7804897B1 (en) 2002-12-16 2010-09-28 Apple Inc. Method for implementing an improved quantizer in a multimedia compression and encoding system
US7940843B1 (en) * 2002-12-16 2011-05-10 Apple Inc. Method of implementing improved rate control for a multimedia compression and encoding system
FI116016B (fi) * 2002-12-20 2005-08-31 Oplayo Oy Puskurointijärjestely
JP2004274212A (ja) * 2003-03-06 2004-09-30 Renesas Technology Corp 画像符号化装置
US7519115B2 (en) * 2003-03-31 2009-04-14 Duma Video, Inc. Video compression method and apparatus
DE602004028927D1 (de) 2003-05-06 2010-10-14 Nxp Bv Videokodierungs- und dekodierungsverfahren und entsprechende kodierungs- und dekodierungsvorrichtungen
US7782940B2 (en) * 2003-08-01 2010-08-24 Polycom, Inc. Methods for encoding or decoding in a videoconference system to reduce problems associated with noisy image acquisition
US7430329B1 (en) * 2003-11-26 2008-09-30 Vidiator Enterprises, Inc. Human visual system (HVS)-based pre-filtering of video data
US7809061B1 (en) 2004-01-22 2010-10-05 Vidiator Enterprises Inc. Method and system for hierarchical data reuse to improve efficiency in the encoding of unique multiple video streams
US7986731B2 (en) 2004-02-06 2011-07-26 Apple Inc. H.264/AVC coder incorporating rate and quality controller
US7453938B2 (en) 2004-02-06 2008-11-18 Apple Inc. Target bitrate estimator, picture activity and buffer management in rate control for video coder
US7869503B2 (en) 2004-02-06 2011-01-11 Apple Inc. Rate and quality controller for H.264/AVC video coder and scene analyzer therefor
US7492820B2 (en) 2004-02-06 2009-02-17 Apple Inc. Rate control for video coder employing adaptive linear regression bits modeling
US20050207501A1 (en) * 2004-03-18 2005-09-22 Sony Corporation Method of and system for video bit allocation for scene cuts and scene changes
US20060062481A1 (en) * 2004-09-21 2006-03-23 Markus Suvanto Apparatuses, computer program product and method for bit rate control of digital image encoder
US7474701B2 (en) * 2004-09-23 2009-01-06 International Business Machines Corporation Single pass variable bit rate control strategy and encoder for processing a video frame of a sequence of video frames
CN101069432B (zh) * 2004-12-02 2015-10-21 汤姆逊许可公司 用于视频编码器速率控制的量化参数的确定方法和设备
US20060174296A1 (en) * 2005-01-05 2006-08-03 Parikh Sandip S System and method for evaluating predictive video decoders
US7403562B2 (en) * 2005-03-09 2008-07-22 Eg Technology, Inc. Model based rate control for predictive video encoder
JP4687216B2 (ja) * 2005-04-18 2011-05-25 ソニー株式会社 画像信号処理装置、カメラシステム、および画像信号処理方法
US9667999B2 (en) * 2005-04-25 2017-05-30 Avago Technologies General Ip (Singapore) Pte. Ltd. Method and system for encoding video data
KR101170799B1 (ko) 2005-05-21 2012-08-02 삼성전자주식회사 영상 압축 방법 및 그 장치와 영상 복원 방법 및 그 장치
US20060280242A1 (en) * 2005-06-13 2006-12-14 Nokia Corporation System and method for providing one-pass rate control for encoders
SG130962A1 (en) 2005-09-16 2007-04-26 St Microelectronics Asia A method and system for adaptive pre-filtering for digital video signals
US7809057B1 (en) * 2005-09-27 2010-10-05 Ambarella, Inc. Methods for intra beating reduction in video compression
US7822117B1 (en) * 2005-09-30 2010-10-26 Ambarella, Inc. Video encoder rate control using bit usage measuring and allocating by macroblock classes
US8160156B2 (en) * 2006-02-01 2012-04-17 Verint Systems, Inc. System and method for controlling the long term generation rate of compressed data
WO2007104266A1 (en) * 2006-03-16 2007-09-20 Huawei Technologies Co., Ltd. Method and apparatus for realizing adaptive quantization in encoding process
US8711925B2 (en) 2006-05-05 2014-04-29 Microsoft Corporation Flexible quantization
US8077775B2 (en) * 2006-05-12 2011-12-13 Freescale Semiconductor, Inc. System and method of adaptive rate control for a video encoder
US7773672B2 (en) * 2006-05-30 2010-08-10 Freescale Semiconductor, Inc. Scalable rate control system for a video encoder
US8831089B1 (en) * 2006-07-31 2014-09-09 Geo Semiconductor Inc. Method and apparatus for selecting optimal video encoding parameter configurations
JP4358215B2 (ja) * 2006-09-27 2009-11-04 株式会社東芝 動画像符号化装置及びその方法
US8254455B2 (en) 2007-06-30 2012-08-28 Microsoft Corporation Computing collocated macroblock information for direct mode macroblocks
US8064517B1 (en) 2007-09-07 2011-11-22 Zenverge, Inc. Perceptually adaptive quantization parameter selection
CN101594525B (zh) * 2008-05-31 2011-08-10 华为技术有限公司 量化参数的获取方法、装置及转码器
US8897359B2 (en) 2008-06-03 2014-11-25 Microsoft Corporation Adaptive quantization for enhancement layer video coding
WO2010017166A2 (en) 2008-08-04 2010-02-11 Dolby Laboratories Licensing Corporation Overlapped block disparity estimation and compensation architecture
JP5550032B2 (ja) * 2008-08-05 2014-07-16 株式会社メガチップス トランスコーダ
US9232226B2 (en) * 2008-08-19 2016-01-05 Marvell World Trade Ltd. Systems and methods for perceptually lossless video compression
US8325796B2 (en) 2008-09-11 2012-12-04 Google Inc. System and method for video coding using adaptive segmentation
CN101510950B (zh) * 2008-10-10 2011-05-18 慧帝科技(深圳)有限公司 一种影像处理装置和方法
US8189666B2 (en) 2009-02-02 2012-05-29 Microsoft Corporation Local picture identifier and computation of co-located information
US8879623B2 (en) * 2009-09-02 2014-11-04 Sony Computer Entertainment Inc. Picture-level rate control for video encoding a scene-change I picture
JP5484083B2 (ja) * 2010-01-14 2014-05-07 株式会社メガチップス 画像処理装置
TWI421798B (zh) * 2010-04-27 2014-01-01 Novatek Microelectronics Corp 影像壓縮之位元率控制方法及其裝置
US8477050B1 (en) 2010-09-16 2013-07-02 Google Inc. Apparatus and method for encoding using signal fragments for redundant transmission of data
CN103748612B (zh) 2011-01-24 2018-04-27 英特尔公司 用于获取、表示、比较和传输三维数据的方法和系统
US9215466B2 (en) * 2011-01-31 2015-12-15 Apple Inc. Joint frame rate and resolution adaptation
US9154799B2 (en) 2011-04-07 2015-10-06 Google Inc. Encoding and decoding motion via image segmentation
US9262670B2 (en) 2012-02-10 2016-02-16 Google Inc. Adaptive region of interest
GB2499843B (en) * 2012-03-02 2014-12-03 Canon Kk Methods for encoding and decoding an image, and corresponding devices
US20140192898A1 (en) * 2013-01-04 2014-07-10 Intel Corporation Coding unit bit number limitation
WO2014107183A1 (en) * 2013-01-04 2014-07-10 Intel Corporation Coding unit bit number limitation
TWI578763B (zh) * 2013-02-28 2017-04-11 英特爾股份有限公司 編碼單元位元數限制
US9392272B1 (en) 2014-06-02 2016-07-12 Google Inc. Video coding using adaptive source variance based partitioning
US9578324B1 (en) 2014-06-27 2017-02-21 Google Inc. Video coding using statistical-based spatially differentiated partitioning
FR3024313B1 (fr) * 2014-07-25 2017-12-08 Allegro Dvt Codeur de video a debit variable
US10419760B2 (en) 2014-09-29 2019-09-17 Sony Interactive Entertainment Inc. Picture quality oriented rate control for low-latency streaming applications
KR101631950B1 (ko) * 2014-11-12 2016-06-20 삼성전자주식회사 전처리기법을 이용한 영상 부호화 방법 및 장치
US10264257B2 (en) * 2015-06-30 2019-04-16 Texas Instruments Incorporated Video encoding
US10178390B2 (en) * 2016-03-30 2019-01-08 Sony Interactive Entertainment Inc. Advanced picture quality oriented rate control for low-latency streaming applications
KR102543444B1 (ko) 2017-08-29 2023-06-13 삼성전자주식회사 영상 부호화 장치
US10979747B2 (en) * 2017-12-21 2021-04-13 Arris Enterprises Llc Statistical multiplexing system for variable bit rate encoding with constant bit rate encoder
US10659514B2 (en) * 2018-03-28 2020-05-19 Arlo Technologies, Inc. System for video monitoring with adaptive bitrate to sustain image quality
CN114363624B (zh) * 2020-10-13 2023-03-31 北京大学 一种基于敏感度的码率分配特征压缩方法

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3735349A1 (de) * 1986-10-18 1988-04-28 Toshiba Kawasaki Kk Bildpresservorrichtung
SE457402B (sv) * 1987-02-20 1988-12-19 Harald Brusewitz Foerfarande och anordning foer kodning och avkodning av bildinformation
US5051840A (en) * 1988-12-14 1991-09-24 Fuji Photo Film Co., Ltd. Device for coding a picture signal by compression
DE69031198T2 (de) * 1989-06-09 1998-03-19 Matsushita Electric Ind Co Ltd Einrichtung zur orthogonalen Transformationskodierung
JPH03129987A (ja) * 1989-10-14 1991-06-03 Sony Corp 映像信号符号化装置及び映像信号符号化方法
EP0444918B1 (de) * 1990-02-28 1996-06-05 Victor Company Of Japan, Limited Einrichtung zur Datenkompression
US5150432A (en) * 1990-03-26 1992-09-22 Kabushiki Kaisha Toshiba Apparatus for encoding/decoding video signals to improve quality of a specific region
US5038209A (en) * 1990-09-27 1991-08-06 At&T Bell Laboratories Adaptive buffer/quantizer control for transform video coders
JP2514111B2 (ja) * 1990-12-28 1996-07-10 日本ビクター株式会社 フレ―ム間符号化出力デ―タ量制御方式及び画像符号化出力デ―タ量制御方法
US5111292A (en) * 1991-02-27 1992-05-05 General Electric Company Priority selection apparatus as for a video signal processor
JP3187097B2 (ja) * 1991-10-17 2001-07-11 株式会社東芝 動画像符号化における符号量配分方法とこれを用いた動画像符号化方法及び装置

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7889792B2 (en) 2003-12-24 2011-02-15 Apple Inc. Method and system for video encoding using a variable number of B frames

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